The name Betsy is a girl's name of Hebrew origin meaning "pledged to God". Betsy and is often added to lists like Nicknames for Elizabeth and discussed in our forums with posts like "Quick Question Thread?!".
From the experts:
This Elizabeth nickname has a decidedly retro feel--think Betsy Ross and the Betsy Wetsy doll-- once seen as a perkier, younger-sounding alternative to Betty. But with Betty on the brink of a comeback, pigtailed Betsy could return as well.
Betsy's height of popularity was from the forties to the sixties, when she was likely to be the radio, film or TV teenaged daughter.